1] fraction), separated by flotation on sodium polytungstate
solution with specific gravity 2.
3] of sodium polytungstate
(SPT) (Sometu Europe, Germany) following a procedure very similar to that used by Six et al.
Instead, sodium polytungstate
solutions were made varying in density up to 3.
If foraminifera were not abundant, as in the Arroyo Colorado samples, they were concentrated for ease of counting using a sodium polytungstate
flotation technique (Callahan 1987).
The SEM micrographs of samples after density separation with sodium polytungstate
([rho] = 2.
Briefly, 10g of air-dried soil (<2 mm) was placed into 40 mL of sodium polytungstate
Briefly, 10 g of air-dried soil (<2 mm) was placed into 40mL of sodium polytungstate
Briefly, 10g of air-dried soil (< 2 mm) was placed into 40 mL of sodium polytungstate
Heavy minerals were separated using a sodium polytungstate
solution at a density of 2.
Briefly, the free light fraction was separated by centrifugation after shaking the soil in a sodium polytungstate
solution of density 1.
Each sample was weighed (20 g) in a 250 mL plastic centrifuge tube (Nalgene) and 200 mL of sodium polytungstate
gently added using a dispenser.
The 53-125 pin fractions were combined for each horizon and heavy minerals were isolated by gravitation in a sodium polytungstate